A2A Protocol API

Direct communication between OpenSIN agents.

Overview

The A2A (Agent-to-Agent) protocol enables agents to communicate directly without going through a central coordinator.

Endpoints

Get Agent Card

GET /v1/a2a/{agent_url}/card

Response:

{
  "name": "researcher",
  "version": "1.0.0",
  "capabilities": ["web_search", "summarization"],
  "protocols": ["a2a"],
  "endpoints": {
    "a2a": "https://api.opensin.ai/v1/a2a/researcher"
  }
}

Send A2A Message

POST /v1/a2a/message

Request:

{
  "version": "1.0.0",
  "type": "request",
  "from_agent": "writer",
  "to_agent": "researcher",
  "content": "Research AI trends for 2026",
  "priority": "high"
}

Message Types

Type	Description
request	Request information or action
response	Response to a request
notification	One-way notification
error	Error message

Next Steps

• Agent API
• Team API